Electrical switch



Dec. 18, 19 1 J. A. ALEXANDER 2,579,135

ELECTRICAL swrrcx-x Filed July 51, 1948 FIG. I. FIG. 5.

FIG. 2.

FIG. 6. He. 7.

FIG. 3.

29 28 is is l9 FIG. 4.

7 20 2| 27 2511 I7 6 IO' l I 2928 25l8 l9 5 FIG. IO.

INVENTOR JOHN"'A. ALEXANDER GYM Z Y ATTORNEYS Patented Dec. 18, i951 UNITED. sTATs-s ears- T OFFICE ELECTRICAL SWITCH John A. Alexander, llacifitPTili sauiles calii. J

Application July 31 1948, Serial No.-41,"7-39 14 Claims, (01.;200-153) This invention has todo with electrical switches or circuit controllers-and has as an object the provision of a switch which is highly economical of manufacture.

Another object is to provide a switch which is positive in action and-providesan ideal type of contact.

A further object is to provide a novel switch mechanism which is-readilyadaptable not only to wall switches and the like but also to relays or multiple pole, multiple throwcontrollers.

Another object is to provide aswitch which has effective safety provisions. f

Still further objects and-accomplishments of my invention will become apparentfromthe following detailed description of specific embodiments thereof, for which purpose I shall now refer to the accompanying drawings, wherein:

Fig.1 is a side elevation, of which isshown a portion in section, of one form of switch embodying the invention. shown in open position;

Fig. 2 is a view similar to Fig. 1 but showing the parts 'inthe first stageof acircuit closing oper ation;

Fig. 3 is a view similar to Figs l and 2,- showing the switch in closed position;

Fig.4 is a view similar to Figs..-i,,2 an .3,' Q

ing the parts in the-position which they occupy during the first :stageof the operation to open the switch;

Fig. 5 is a top plan view;

Figs- 6 and 7 :are enlarged cross sections ,on lines 6-6-and 1 1 of Figs. 1 and 3;:r Snectiyely.

Fig. 8 is asideelevation,-a,portion"bei Shown in section, of 'a-modified form .of the invention, showing an embodiment as a double pol double throw switch;

Fig.9 is a front elevationiof the .device shown in Fig. 8.

Fig. 10 is a bottom pl-anview .oi-the same device,

and--' Fig-ll is a fragmentary detail showing another modification.

Referringfirst to the -:embodiinent of Fi .5.. l-fl. the numeral 5 generally indicates a body conistine of a base 5 cerr w g nd uprightsifi a "I; the base and-uprights being shown as madeof a; suitable non-cond ct ve ma e al; such as a u tame pl stic.- i dcs ech he s odywmay be mounted-iniarhoufin 'notshownr;

.a tiansvcrseppcnings r c i icd i rcugh unht @130. slidaloly: ran actuating pl-unge ill whic isIQaQcdbYa-srrmg 1.5 ct ng bctwc nthc upr ghtfiaand a; push b. 1 :16 onthe-outersnd f t e sp uns rl: A c llar :4 l ;1. ;1i2 6.1=;=01@ the P ln -Q at the opposite side, of the upright to limitymovement :of the plunger outwardly or to the right under influence of the spring. The plunger has a reduced diameter left-hand or inner end portion IB providing an annular shoulder l9 atits, point of intersection-with the contiguous portion f h plun' 'r. for the purpose to be des ribed-J A.:pair of resilient arms 10, 1 are each rigidly securedtothe upright 1 :by; meansof bol -tsand nut units 23, 24, the latter of which provides atermi-e nal towhich one wire v(not shown) of an electrical circuit is adapted to be connected. I

A third resilient arm .25. is;.secured to thepase by means :or bolt .and screw unit 26, which later serves as a terminal for the other leg of the ctr: cuit.

'I prefer to make the.arms-$20,;21;,25i0hordi; nary leaf springs-,andonly one end ofteach is chored.

Retaining arm 2.051s provided between its ends 4 with an opening 21 -to receive the reduced upper end 25a of arm 25, the right hand end of the opening serving a n abutmen 11. 1 :2. 5.1% tolock'the switohin closed position (Fig. 3);. The outer or :free end .of arm :2I is upwardly curved for efiicient contact with arm 25 in circuitclosing;. posi-tion:; ,an'dgthe outer or free end of arm 20 is diagonallydownwardly disposed to facilitate its engagement with the shoulder l9 to of,- fec-t opening of the switch for disengagement of the reduced endg25a with the abutment.

'I'olimit downward swinging movement of arm 2| I provide a post 28 having a diagonal .upper face 29. The post 28 also serves as a stop to limit flexure in one direction of arm 25.

The spring arm- 20 is prestressed to cause i-trto bear downwardly against -the free end of arm: 25; arm 3-2l .is prestressed to causeit to bear-against the post :23 and arm 25 is prestressed to cause'it to pull away from thefree-end of arm 21-, as well as to snap out. of the openin :21 during gtheswitch opening movement, all as best appears in.Fig 1. The outer endjportionsofarms 2! andidmay be considered as contact-elements. and theprestressed inner end portions adjacent the -base 5 may be considered as means for biasing the contact elements to their above described normal positions: 1 v

In op rat on. comm ncing with the parts in the open position of Fig.-- i, to .closethe switch the phmscr ;l 0 "i push in ds. he sit-ion? of Fig. 2. causing arm 25 to engage .the curved end 0f armZl with a rubbinglaction so desirableto ideal. contact, .and permitting the reducedend .25aof arm 25.7120 snap into.,the

opening 21. Upon release of the plunger the spring l5 returns it to the position of Figs. 1 and 3, the collar acting as a stop against further outward movement of the plunger, and the free end of arm 26 snaps into the position of Fig. 3, in the path of shoulder l9 for the next subsequent operation. Inasmuch as the end 25a, of arm 25 is engaged in the opening 21, the switch is held in that closed position until the plunger is again operated to open the switch.

To open the switch from the position of Fig. 3, the plunger is again pushed inwardly, the

shoulder l9 engaging the free end of arm 20 and bowing the arm upwardly until the reduced end 2512 of the arm 25 is released from engagement in the opening 21, which takes place automatically since the arm 25 is 'resilientand is stressed to flex to the right to the position of Fig. 1. Release of the plunger then permits the parts to return to the position of Fig. 1.

In Figs. 8 and 9 and 10, I show an adaptation of my invention as a double pole, double throw switch.

Here the L-shaped base or body 30 has secured to its lower end 30a a bifurcated insulating pad 3|, the pad being secured as by screws 32. The lower end 30a presents a slot 34 in which a contact plate or actuating arm 35 is pivoted to swing, the plate having cutaway portions 36 tofit in the slot.

A'coil or electro-magnet 46 has its core 4| secured to the upright portion of the body as by a screw 42, the outer end of the core being disposed for contact with the swingable plate 35 when the electro-magnet is energized through wires W, W. Secured to one of the branches 3|a of the bifurcated pad 3|, as by screws 31, with insulating strips 38 between and on each side of them, there are three resilient contact arms Like arms 45a, 46a, 41a are secured to the other branch 3 lb of the pad 3| as by screws 49. The medial arms 41, 41a have secured to their free ends a cross bar 50 of insulating material, the cross bar having a medial upstanding finger 5| for the purpose to be described.

' A pair of contact elements 52, 53 are secured, one on each side of arm 4'! adjacent the upper end thereof, and a like pair of contact elements are secured on arm 41a.

Each of the arms 45, 46 has a contact element 56, 51 respectively, secured on its free end for alternate engagement with the contact elements 52, 53 in response to movement of the arms 41, 41a.

To normally urge the plate 35 away from the core 4|, I provide a coil spring 60, one end of which is secured to the lower end of the plate and the other end of which is secured to a depending bracket 6| mounted on the base portion 30a. 4 Thus the outer end portion of the slot 34 in the body portion acts as a fulcrum for the plate 35.

"Plate 35 carries an arm 63 extending upwardly therefrom with its top end disposed for engagement with the cross bar 56 when the coil is ener gized. Arm 63 has a lateral projection 65 presenting an upwardly opening notch 66; A downwardly curved leaf spring 61 is secured at one end to the upright portion of the body by a screw 68 and is stressed to bear toward the cross bar 56. The spring arm 6! has a hole 69 into which the finger 5| on the cross arm enters in one position of the switch. The outer end of arm 61 bears towards the projection 65 and its free end is disposed to enter the notch 66 in one-po ition The device described, being of the double pole, double throw variety, is adapted to control four circuitsthat is, leads are attached to each of the arms 45, 46 and a common return lead is attached to the pole arm 41 while leads are also attached to each of the arms 45a, 46a, and a common return lead is attached to the pole arm 41a.

Operation of the device is as follows: In the position of Fig. 8 the electro-magnet is deenergized, permitting the spring 6|) to swing the plate 55 to the right. The medial arms 41, 41a are prestressed to bear to the right so that contacts 53 engage the contacts 51, thus closing two of the circuits. The switch elements are maintained in that position not only by the resiliency of the arms 47, 41a, but also by the spring 61 bearing downwardly against the finger 5| to frictionally oppose movement thereof. To open the last mentioned circuits and to close the other circuits through arms 45, 45a, 41, 41a, the electromagnet is energized momentarily to draw the plate 35 against the core and to cause the free end of arm 63 to engage and move the cross bar 56 and thus to swing arms 41, 41a to the left to cause the contacts 52 to engage the contacts 56, and to cause the contacts 53 to disengage from contacts 51. The parts are held in this position by the finger 5| engaging in the hole 69 of the spring arm 61. Then, to open the latter circuits and to return the parts to the position of Fig. 8, closing the first mentioned circuits, the coil is again momentarily energized, drawing the plate 35 and its carried arm 63 towards the core. This movement of arm 63 causes-the notch 66 in the projection 65 to engage the free end of spring arm 61 and bow said arm upwardly sufficiently to free the finger 5| from the hole.

The electro-magnet being then de-energized, the arms 41, 41a swing to the right by virtue of their own resiliency to cause the contacts 53 again to engage the contacts 51.

It will be observed that at no time is it necessary to hold the electro-magnet energized since a momentary energization causes full actuation of the switch elements.

In Fig. 11, I show a modification wherein the parts are as before described and are given like reference numerals, excepting only that here I provide a stop or abutment to limit the extent to which the leaf spring arm 61 may be bowed outwardly in the course of its flexure by the arm 65. Here I secure to the upright portion of the body 30, as by a screw 10, a plate H to which I fix an insulating pad 12 in position to be engaged by the spring 61 after limited upward bowing movement.

While I have described three specific adaptations of my invention in rather minute detail, I

wish it understood that within the broader scope of the invention as defined by the appended claims, other embodiments, which will become apparent to those skilled in the art from a reading of the foregoing explanation, are possible.

I claim:

1. In an electrical switch: a body; a pair of contact elements carried by said body, at least one of which is movable relative to the other alternatively into two positions, one of which is a position of contact of the two elements with each other and one of which is an open position; biasing means holding the movable contact element in a first one of said two positions; a spring arm carried by the body, said arm carrying an abutment catch engageable with the movable its movement in5said tone directionz being-such thatsit engages and. flexes said :spring armaaway from said positioneofaaengagement of: said patch with said :movableacontact element,- whenethe spring arm is-in :rsa-id engagement position, and the path of-Jnovemen-t of said means inwsaid o directionebein renal-r:thatv it :aJSo rails-to thus ansage and; flex,-,said-. spring arm, ewhenssaid spring armqi-s not iinl-saidcengagement position, ,w-hereby upon :a second. movement of said resiliently re tractable. .mernber' in said one. direction, .said movable contact element isldisengaged from said catch and as lfree .41.0 lreturn tolits-zfi-rstrposition under ,the action; ctr-its ,biasinglmeans. I

52. Thecom-binaetiontdefinedin ,clai-mal in which said spring arm-is .a leaf spring; secured at one endto .the body with its outer portion overlying the lmovableelement, the l, abutment catch bein provided on the spring; arm betweenrits ends; and inrwhichsaidameans movable with lth e retractable member engages the -.,outer endof thespringfor said flexingaction-H 3. The combination zdefinediiniclaim-fi .in which thetcatch abutment is. the -endvwallroflalongitudie nally extending. slot :in -,.the .leaf. spring arm, and thecouter end of themorablacontact element, is shaped-with a tong-ue to enter saidslot,

)4. Thecombinationrdefined inrclaim l in which theresiliently retractable mova'ble member is the armature of an ,electromagnet; and in addition thereto an electromagnet for said armature,

.a-nelectricalflswitch, a body carrying a first contact element and a resilient second contact elementroomprising'a spring arm anchored to the body at one end only, flexible to bring its movable end'into contact "w'ith said first contact element and prestressed to normally move its movable -ei'1d-:aw'ay from: the first contact element, aretaining arm resiliently swingableto bear constantly against the-.outer end portion of said second-:contactelement, saidend portiontbeingcontactually slidable lengthwise of th mm. ing: arm as the second contact aelement: moves relativelyto the first contactelement, said2arm havmg-aan abutment engageable by the FOUTbBI' :end Portionof said second con-tact element as, it slides ailongitheq-retaining arm to catch "and retaini'fthe second contact element in contact position, and means carried by the body for movement into position flexing said arm sufficiently to free said second contact element from engagement with said abutment.

6. In an electrical switch, a body carrying a contact element, a resilient contact arm secured at its inner end to the body and disposed for engagement at its outer end portion with the contact element, said arm being stressed to bear awayisfrcm eeng-agement wlthasaid rcontact 19m ment,-aaileaf spring secured atrits inner end the --body-:.and overlying :zand ,;stresscd:to bear, against zthe outer. :end ,ofisaid zarrn, saidlarmzhaving an 4 outer end. proiection and said deaf spring;

presentingza transverse :hole. adjacent said prov jectionpositioned toreceiizersaid:projection when: the 10011173017 arm; is :in engagement with the cone tact lelementga "plunger 'slidably: mounted, inst/1'16,

body, the plunger being engageable during tea-first; movementof the :plunger with said. contact arm to move the-latter into engagement with thecontact aaelement, and ran abutment on the plunger positioned 1-=t0 engage :the outer end 1- of the-leaf springwhenithe project-lends engagedinsaidhole whereby a :second'imovement' ofthe plunger tunetionseto .engagesaid abutment with thecuterend of;the. leafspringandrto flex the latter -sufil,cientl yl to idisengage atheprojectionafrom the. hole.

"1;: In-r-anxlelectrical switch, a :bodycarryinga contact element, .;a resilient contact aarmlsecured at itsrinnerz-end to the :body andvdisposedfor tengagement at its .outer end portion with the contact element, said arr-n being bowed toward and stressed :to bear away from en agementwithzsaid contact element, a leaf -spring secured at ,its'in'. ner end to the body and overlying and-stressed to .,:bear against the outer end of -said arm, said arm rhaving an outer send projection-andsaid leaf spring presenting a transverse hole adjacent said projection positioned to receive said projec tion when the contact armis; imenga-gemen-t with the contact element, a plunger slidablymounted in the :body, the plungerbeing-engagement during .a first movement of the plunger with :sald contact arm-to move the latter into engagement with the contact element, .and :an abutment on the plunger positioned to enga ethe outer end of the leaf spring when the projection deb-engaged in said hole whereby a second movement. ofthe plunger functions to engage said .-abutment with the outer end of the. leaf. springwand to flexthe latter sufficiently to disengage the projection from the :hole. 7

8. Inan electrical switch, a-bod-y carrying :a contact element, -a r-resilient contact arm secured at its inner-end to the body and disposedzfor engagement at itsa-outer end portion with the con tact element, said arm being .stressedtyto-bear away fmmengagementwith-saidcontact element, at leafv spring secured at its innerend to-the body-and overlying and stressed .to bear against the outer .end of said arm, said arm having. an

- outer end proaectionandisaid leaf spring present-s ing a transverse hole adjacent said projection positioned to receive said projection when the contact arm is in engagement with the-contact element, .a.plunger slidably mounted in thebody, the plunger having a reduced diameter outerend portion lengagcable during .:a -:first v-moaementof the. plunger with said-contact arm i-to move the latter -intc-;eng e ment with the contact element, said reduced V=diameter outer .end portion provid ing an annular shoulder atritsepointuofsinten section with, the :larger diameter portion: of the plunger-which said vshoulder is positioned toengage the outer end of the leaf spring upon a second movement of the plunger and to flex the leaf spring sufficiently to disengage the projection from the hole.

9. In on electrical switch, a U-shaped body having secured to one of its sides a flat spring contact, and a leaf spring retainer having an opening between its ends and overlying said contact, a leaf spring contact secured at one end to-the bottom portion of the body, the leaf spring contact being bowed towards the flat spring contact, having an end projection terminating in engagement with said retainer and being stressed normally to bear away from the flat spring contact, and a plunger slidably mounted in the other side of the body having two transversely arranged faces, one for engagement with the leaf spring contact and one for engagement with the outer end of the retainer.

10. In an electrical switch having a movable resilient contact presenting a projection, and a plunger having two transversely arranged faces, a first one of said faces operatively engaging said contact, a retainer for releasably holding said contact in a circuit closing position, said retainer comprising a leaf spring anchored at one end and having its free end disposed to be engaged by the second of said plunger faces, said spring having between its ends a hole to receive said projection of the resilient contact.

11; In an electrical switch, a body, a pair of resilient contact arms carried by the body, the first of which is flexible into engagement with the other, actuating means'for flexing said first arm into rubbing engagement with the other to close a circuit, and a leaf spring secured at one end to the body, said spring having an abutment engageable with said first arm to hold it in circuit closing position, said actuating means being disposed for engagement with said spring to flex it suificiently to release the first arm from the abutment.

12. An electrical circuit controller comprising an electro-magnet carried by the body, an actuating arm hingedly carried by the body for swinging movement in one direction in response to the electro-magnet, spring means urging the arm in the opposite direction, said arm presenting a notch, a leaf spring fixed at one end to the body and normally bearing at its other end toward but spaced from said arm adjacent the notch, said leaf spring having a transverse opening therein, two sets of relatively movable contact elements mounted on the body at opposite sides of the leaf spring, and a cross arm of nonconducting material carried by and extending from a movable contact element of one set to a correspondingly movable contact element of the other set in the path of movement of the actuating arm, said arm having a projection engageable in said opening in the leaf spring when said movable contact elements are moved into circuit closing position by movement of the actuating arm against said cross arm, and said leaf spring being flexible in response to movement of the actuating arm when the outer end of the leaf spring is engaged in said notch to disengage said projection from said hole, said engagement of the projection with the said opening permitting movement of the outer end of the leaf spring into contact with said actuating arm adjacent said notch and into engagement with said notch upon movement of said actuating arm.

13. An electrical circuit controller comprising a pair of spaced resilient electrically conductive arms each of which is adapted for connection to a lead wire of an independent circuit, means anchoring said arms at one end only, a contact element carried by the free end portion of each of said arms, a third electrically conductive resilient arm disposed between the first mentioned arms and anchored at one end, said third arm being adapted for connection to a return lead wire common to both said independent circuits and having at its free end portion opposed contact elements positioned for alternate engagement with the first mentioned contact elements, the third arm being prestressed to be urged by its resiliency away from one of the first mentioned contact elements and into contact with the other of said first mentioned contact elements, actuating means for moving the third contact arm in the opposite direction, retaining means for releasably holding the third arm at the end of the last named movement, and means controlled by and operable with said actuating means for releasing said retaining means.

14. An electrical circuit controller comprising a pair of spaced resilient electrically conductive arms each of which is adapted for connection to a lead wire of an independent circuit, means anchoring said arms at one end only, a contact element carried by the free end portion of each of said arms, a third electrically conductive resilient arm disposed between the first mentioned arms and anchored at one end, said third arm being adapted for connection to a return lead wire common to both said independent circuits and having at its free end portionopposed contact elements positioned for alternate engagement with the first mentioned contact elements, the third arm being prestressed to be urged by its resiliency away from one of the first mentioned contact elements and into contact with the other of said first mentioned contact elements, actuating means for moving the third contact arm in the opposite direction, retaining means independent of its electrical contact surface for contactually engaging and releasably holding the third arm at the end of the last named movement, and means responsive to an independent movement of the actuating means in the last named direction, to release said retaining means.

JOHN A. ALEXANDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Logan Sept. 18, 19 

